I. Field of the Invention
The invention relates to a method of and apparatus for the improvement of heat transfer from a hot component made of a material having a low thermal conductivity. The invention is particularly, but not exclusively, concerned with the cooling of a hot engine component.
II. Description of the Prior Art
It is common practice to circulate oil or other coolant through passages in or adjacent a hot component and to cool the coolant remotely from the hot component for example in a heat exchanger or to allow it to cool in a sump. Usually the flow of liquid coolant through the coolant passages is laminar. By designing the coolant passages for turbulent flow, an improved cooling effect can be achieved, but as the passage walls are necessarily of smaller surface area for turbulent flow than for laminar flow, high temperature gradients may be produced near the coolant passages. An object of the present invention is to design the coolant passages for turbulent flow and to provide for a higher rate of thermal conduction from the vicinity of the coolant passage walls in a component made from a material of comparatively low thermal conductivity.